Because I knew that if I kept posting in a different color, that one day you would finally ask me why I always type in a different color.

Seriously though, the reason I use a different color is to seperate the quote from what I am typing. It's an optical thing, especially when I multi quote. It seems to be easier to read when I do it that way. So I figure if it is easier for me to read, then it has to be easier for others as well.